1. Technical Field
The present invention relates to the field of metrology targets, and more particularly, to metrology targets for combined imaging and scatterometry measurements.
2. Discussion of Related Art
Metrology targets are designed to enable the measurement of parameters that indicate the quality of wafer production steps and quantify the correspondence between design and implementation of structures on the wafer. Imaging metrology targets as specific structures optimize the requirements for device similarity and for optical image measurability and their images provide measurement data. Scatterometry metrology targets on the other hand, yield diffraction patterns at the pupil plane, from which target parameters may be derived.